This invention relates generally to a container for holding and heating water in a portable solar heating device and more particularly to a removable container that can be handled and used safely, without the risk of injury to the user from inadvertently spilled hot water and without the risk of damage to the container or the heating device from steam pressure or overheating.
Until now, there has been no safe, practical means for heating water, for beverage use, within a container that is held inside the heating compartment of a portable and positionable solar heating device such as a solar oven. A problem arises because the outer casing on a solar oven, or similar device, must be rotated and repositioned often, in order to keep it pointed towards the incoming rays of the sun which are the source of its heat energy. If the heating compartment is a fixed part of the outer casing of the solar oven and moves with it, a water container inside the compartment is subjected to the same movements. Furthermore, if the container rests upon the interior surface of a hinged compartment access door, as it does in the most practical versions of solar ovens, the container is also subjected to rotational movements whenever the access door is opened or closed. If the container has an open spout, these movements, in addition to the movements of inserting and removing the container from the compartment, create extremely hazardous conditions for injury to the user by spilled, scalding water. An open, unobstructed spout is a necessity if water is to be boiled in any container, to release steam and prevent pressure buildup in the container. With conventional water heating methods and containers, an open spout poses no particular problem, since the container always stands upright and is tilted only to remove the heated water. However, in a portable, positionable solar heating device, an open spout is a major problem.
A second problem is that the steam escaping from an open spout must not be released inside the compartment of the solar device where it can cause damaging condensation and water leakage from the compartment. A third problem is that unless there is good, conductive heat transfer between the heated wall of the container and the water in the container, excessively high temperatures could develop on the container walls and damage them. A fourth problem is that the removal of a hot container of boiling water from the compartment of a solar device, and handling the hot container, can cause burn injuries to the user. All of these problems have inhibited the invention and development of a completely safe method for heating water, for beverage use, within portable and positionable solar heating devices.